This invention relates to a refrigerator which has a freezer compartment within a thermal cabinet and, in particular, an evaporator for direct cooling and an evaporator for producing a cold blast in the freezer compartment.
In general, thermally insulated refrigerator cabinets have a first inner compartment for use as a freezer and a second inner compartment for use for refrigeration. Both compartments are inside a single outer cabinet with the spaces between the outside surfaces of these inner compartments and the inside surface of the outer cabinet filled with thermal insulation material.
Refrigerators constructed with this kind of thermal insulation include the direct cooling type in which the freezer compartment is formed by the evaporator itself and, as shown in U.S. Pat. Nos. 4,044,570 and 4,077,229, the cold blast circulation type in in which the freezer compartment is divided into a freezer compartment proper and an air passage, with this air passage having within it an evaporator for the freezer compartment and a fan for directing a cold blast into the freezer compartment. The evaporator is inserted into the freezer compartment through the front opening.
In the direct-cooling type of freezer compartment, the rate of cooling of food placed in contact with the wall surface is rapid, but that of food placed away from the cooling wall surface, e.g. on a shelf, is slow. In contrast, the rate of cooling of food placed away from the walls in the cold blast circulation type is rapid compared with the direct-cooling type, but slow when the food is placed against the walls.
In order to overcome this disadvantage, efforts have been made recently to provide a type of construction in which food is placed in a cold blast circulation type freezer compartment and an auxiliary evaporator is provided which cools the food by direct contact.
But in this kind of construction, since both the main evaporator for producing the cold blast and the auxiliary evaporator for cooling the food by direct contact are positioned within the freezer compartment, the work involved in routing the pipes for these two evaporations to the outside of the inner freezer compartment and connecting them with the piping system of the rest of the refrigerator which includes the evaporator for the refrigeration compartment, is extremely difficult, and owing to this difficulty there is a risk of poor connections.
The object of this invention is a refrigerator in which, firstly, the work of connecting to the refrigeration cycle system which includes the main and auxiliary evaporator of the freezer compartment, is easy and not prone to poor connections. Secondly, the object is to permit the freezer compartment to maintain a high degree of rigidity so that it can withstand the load imposed upon it by fixtures such as the main evaporator and auxiliary evaporator.